1. Field of the Invention
The present invention relates to a display device, and more particularly, the present invention relates to an organic EL display device that includes at least three light emitting regions arranged to achieve high quality image display by providing smooth vertical lines and slanting lines.
2. Description of Related Art
As a wide variety of information processing apparatuses have been developed in recent years, there is a growing demand for flat display devices having a reduced thickness and which operate with lower power consumption than conventional cathode-ray tube (CRT) display devices. Examples of the flat display devices include, for example, liquid crystal display devices and electroluminescent display devices (hereinafter referred to as EL display devices). Among them, the EL display devices have been actively studied because of their features of a low voltage drive system, being made of solid material only, quick response and a self-light-emitting property.
In general, a full-color EL display device includes a display region in which light emitting regions R which emit red (R) light, light emitting regions G which emit green (G) light and light emitting regions B which emit blue (B) light are regularly arranged. For example, Japanese Unexamined Patent Publication No. 2002-221917 discloses a true delta configuration of the light emitting regions.
FIG. 19 is a schematic sectional view illustrating an organic EL display device 5 of Japanese Unexamined Patent Publication No. 2002-221917 including the light emitting regions R, G and B arranged in the true delta configuration.
In the organic EL display device 5 including the light emitting regions R, G and B arranged in the true delta configuration, wherein pixels, each of includes a set of the light emitting regions R, G and B (surrounded by a thick line in FIG. 19), are arranged in a staggered configuration. In the organic EL display device 5, the light emitting regions which emit the same color light are not adjacent to each other. Instead, three light emitting regions which emit different color lights, respectively, are adjacent to each other. The three adjacent light emitting regions are arranged such that the centers of gravity thereof form a triangle, which is a regular triangle.
With the organic EL display device 5 including the light emitting regions arranged in the true delta configuration, smooth slanting lines are displayed. Therefore, the organic EL display device 5 allows display of pictures composed of many slanting lines.
FIG. 20 is a conceptual view illustrating a vertical line produced by the organic EL display device 5. As shown in FIG. 20, the pixels in the organic EL display device 5 are arranged in the form of T (or inverted T). That is, the three light emitting regions R, G and B form or are surrounded by a virtual T (or inverted T) as shown by the dark peripheral lines surrounding each set of the three light emitting regions R, G and B in FIG. 19. Therefore, a plurality of jagged edges occurs along a vertical line extending through the center of the T or inverted T arrangement. Thus, the organic EL display device 5 including the light emitting regions arranged in the true delta configuration cannot have smooth, non-jagged vertical lines.